Colour Blindness – Overview Colour blindness is a common visual condition that affects a person’s ability to perceive certain colours accurately. Most individuals with this struggle to differentiate between shades of red and green, although other forms can impair blue and yellow recognition. In very rare cases, a person may not see any colour at all, a condition known as achromatopsia. This condition occurs when the cone cells in the retina—the part of the eye that detects light and colour—do not function properly. There are three types of cone cells, each responsible for detecting red, green, or blue light. If one or more types of cones are missing or defective, colour vision is altered. This can result in difficulty identifying colours, confusion between similar hues, or limited colour perception. The majority of cases are inherited and present from birth. this is usually passed down through the X chromosome, which makes it far more common in males than in females. Approximately 8% of men and 0.5% of women of Northern European descent are born with some form of colour vision deficiency. However, acquired this can also occur later in life due to disease, injury, or exposure to certain medications. Colour Blindness – Overview Colour blindness does not lead to total vision loss, nor does it typically cause other eye issues. However, it can impact daily life in subtle ways—such as selecting ripe fruit, reading colour-coded maps or graphs, interpreting traffic lights, or choosing matching clothes. In children, undiagnosed colour blindness can affect performance in school, especially in early years when colour-based learning is common. Although there is no cure for this inherited condition, many people adapt well using learned coping strategies. Special lenses, mobile apps, and classroom accommodations can help reduce the challenges it presents. In summary, colour blindness is a non-progressive visual difference that limits colour perception. While it can’t be reversed, it is manageable, and those affected can lead entirely normal and productive lives. [Next: Causes of Colour Blindness →]